This invention relates to measurement gages, and more particularly to an improved two-point measurement gage for measuring internal diameters and the like. Even more particularly, this invention relates to a two-point measurement gage which characteristically has a wide measurement range as well as high accuracy and precision.
Conventional I.D.(internal diameter) measurement gages fall into three general categories: two-point measurement gages including calipers and micrometers, three-point measurement gages including bore and plug gages, and three-point bench top gages. Both classifications of three-point gages have accurate measuring capabilities, but they are limited to small measurement ranges. In addition, the three-point bench top gages are costly to use due to the timely mastering requirements and the expensive set of ring masters that is needed. The two-point measurement gages are capable of measuring over wide ranges, however, most conventional two-point gages generally have difficulty repeating measurements.
One particular two-point gage, as disclosed in U.S. Pat. No. 4,208,796, features a floating, adjustably cross-sliding work table which allows an operator to align the part to be measured with respect to the gaging fingers, and a plurality of control means for affecting either the gaging pressure, the precision screw assembly, the indicator or the work table. With that gage the number of parts and their intricate assemblage, results in a rather high cost of production. Another two-point gage, as disclosed in U.S. Pat. No. 2,953,854, features a pin carrying leg which actuates a dial indicator by means of an extension held against the leg by a spring. This device, however, is limited by the fact that the second leg, and the gaging finger thereon, is fixed against movement.
A gage of the type described in U.S. Pat. No. 4,326,336 does not fit into any of the above-mentioned categories, but this gage employs a V-shaped block for positioning the object to be measured in relation to a plurality of adjustable measuring devices. In such an application, the V-shaped block does not function to centrally align the object to be measured, but rather to maintain the object in a position where measurements may be obtained.
It is therefore an object of this invention to provide a two-point I.D. measuring gage having a wide measuring range and a high degree of precision and accuracy within that range.
It is also an object of this invention to provide a two-point measuring gage of the type described which does not require an elaborate set of ring masters for its calibration.
It is also an object of this invention to provide a two-point measuring gage of the type described which may be quickly and easily mastered for each particular measuring operation.
Another object of this invention is to provide a two-point measuring gage having an adjustable gaging force in order to produce accurate measurements on pliable objects.
Yet another object of this invention is to provide a two-point measuring gage which may be simply manufactured.
Other objects of this invention will become apparent when the preferred embodiments and the accompanying drawings are considered in conjunction with the appended claims.